Data of the flank eruptions of Etna from over the last 400 years were
extracted from the new geological map for the lava flow extensions and
vent positions, and from the catalogs of historical eruptions for the
eruption durations and lava volumes. The partially or widely hidden lava
fields on the new geological map were retrieved from older geological maps.
The distributions of the eruption durations and lava volumes were
analyzed, with the definition of six eruptive classes for use in numerical
simulations. The threshold values for the eruption durations and lava
volumes were set at 45 days and at 35 × 106 m3 and 100 × 106 m3,
respectively. A global analysis was performed on the whole volcano to
evaluate the recurrence of the classes, and to estimate for each class the
ranges, means and standard deviations of the durations, volumes and
elevations of the main vent. The same analysis was repeated by
subdividing the volcano into three sectors, which were defined on the basis
of the distribution of the eruptive fissures over the last 15 ka. The classes
have different recurrences across these various sectors, and different
distributions of volumes, durations and elevations of the main vent.
Finally, a lava flow resurfacing map that counts the number of lava flows
on each given area of the volcano over the last 400 years was compiled
and then normalized.